Umbilicaria phaea var. coccinea is endemic to northwestern continental United States. It is a distinctive and conspicuous species due to its bright red thallus. Therefore, it is unlikely to have been overlooked in areas that have been explored by lichenologists or by general botanists. It is only known to be locally common in the arid portions of a single watershed. There are approximately six sites outside of this watershed with very small populations.
Northern California, Oregon, Washington.
It is locally somewhat common in arid portions of the Klamath River watershed on both sides of the California/Oregon border. Outside of the Klamath River watershed there are approximately four known sites with small populations (one to a few small thalli) in central Oregon and two sites in Washington along the Columbia River, which are also small populations.
In arid environments on exposed basalt and ultramafic rock.
Development, habitat loss.
In Washington, the Northwest Lichenologists conducted a review and they recommended a state conservation rank of S1 (critically imperiled). This is currently under review by the Washington Natural Heritage Program. In California, this variety is considered rare (Sharnoff 2014). A bid for conservation sponsorship is currently being prepared for the Conservation Committee of the California Lichen Society by J. Villella and E. Peterson. In Oregon, U. phaea var. coccinea has a Natural Heritage state rank of S2 (imperiled).
The much more common brown variety, Umbilicaria phaea var. phaea, almost always occurs adjacent to the red variety. It is uncertain if the the two varieties are interbreeding. Further research is required to better understand their relationship, which may be important for conservation planning.
Climatic models show potential habitat in eastern Washington and eastern Oregon that may not have been explored (McMullin et al. In review).
Llano GA. 1950. A Monograph of the Lichen Family Umbilicariaceae in the Western Hemisphere. Navexos P-831. Office of Naval Research, Washington, D.C.
McCune B, Geiser L. 2009. Macrolichens of the Pacific Northwest, second edition. Oregon State University Press, Corvallis, OR.
Oregon Biodiversity Information Center. 2013. Rare, Threatened and Endangered Species of Oregon. Institute for Natural Resources, Portland State University, Portland, Oregon.
McMullin, RT, Braid HE, McBride P, Peterson E, Villella J, Sheehy S, Glew K, Newmaster SG. A conspectus of Umbilicaria phaea var. coccinea: including its conservation status and continued support for its variety rank from four molecular loci. In review..
Peterson E. 2003. Clarification of three Umbilicaria species new to California. Bull Calif Lichen Soc 10: 10 .
Sharnoff S. 2014. A field guide to California Lichens. Yale University Press, New Haven, Connecticut.
Washington State Department of Natural Resources. 2014. Washington Natural Heritage Program Proposed List of Rare Lichens. www1.dnr.wa.gov/nhp/refdesk/lists/lichens.html Accessed 25 February 25 2015